Ifeel like the answer is number 4 but im not sure. what was the key factor in creating the earth's early atmosphere? respiration of single-celled organisms photosynthesis of land plants violent storms outgassing by volcanoes

What does resonance result in? quieter sounds frequency amplitude louder sounds

Which pair of sentences is describing the same velocity? a. a car is parked. a car is moving in circles. b. a bus drives 40 miles per hour north. a truck drives 50 miles per hour north. c. a boy walks east at 6 kilometers per hour. a girl walks west at the same speed as the boy. d. valerie rides her bike south at 8 kilometers per hour. owen jogs south at 8 kilometers per hour.

For which of the following ions is the intracellular concentration typically higher than the extracellular concentration? a. sodium b. calcium c. magnesium d. potassium e. chloride